This supernova event may have occurred at the Upper Centaurus Lupus Society. This is a group of giant stars about 457 light years away from Earth.
Illustration of an exoplanet like Earth after X-ray radiation exposure. Image credit: NASA/CXC/M. Weiss.
Life on Earth is constantly evolving under continuous exposure to ionizing radiation from both terrestrial and cosmic origins.
The radioactivity in the bedrock gradually decreases over timescales of billions of years, but the level of cosmic radiation fluctuates as the solar system moves through the Milky Way.
Nearby supernova activity could increase the level of radiation on the Earth’s surface by several orders of magnitude, which is expected to have a major impact on the evolution of life.
In particular, radiation levels improve as the solar system passes near a large group of stars known as the OB Association.
The winds associated with these large star factories are expected to inflate the super bubbles of high temperature plasma first. This could be the birthplace of most of the Core Collapse explosions taking place within the AB Association.
The solar system entered such a super bubble, commonly known as the local bubble, about 6 million years ago, and is now close to its centre.
“The Earth entered the local bubble and passed its stardust-rich appearance about 6.5 million years ago, sowing the planet with old iron 60, the radioactive iron of iron produced by the exploding stars. did it,” astronomer Santa Cruz, and colleagues at the University of California.
“Then, 20-3 million years ago, one of our neighboring stars exploded with incredible force, providing another cohort of radioactive iron to the planet.”
When Nojiri and her co-authors simulated what the supernova looked like, they discovered that it hammered the Earth with cosmic rays for 100,000 years of explosion.
This model perfectly described previously recorded spikes of radiation that shocked the Earth around that time.
“We’ve seen from other papers that radiation can damage DNA,” Nojiri said.
“It could be an evolutionary change in the cell or an accelerated mutation.”
Meanwhile, the author came across research into viral diversity in one of the Rift Valley Lakes in Africa.
“I can’t say they’re connected, but there are similar time frames,” Nojiri said.
“We found it interesting that the virus’s diversification is increasing.”
study It was published in Astrophysics Journal Letter.
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Caitlyn Nojiri et al. 2025. Bubble Life: How nearby supernova left short-lived marks on the cosmic ray spectrum, leaving an indelible trace of life. apjl 979, L18; doi: 10.3847/2041-8213/ADA27A
Source: www.sci.news
